u-boot/board/esd/ocrtc/cmd_ocrtc.c
Wolfgang Denk 54841ab50c Make sure that argv[] argument pointers are not modified.
The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands.  Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".

This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:

int main (int argc, char **argv)
{
	while (--argc > 0 && **++argv == '-') {
/* ====> */	while (*++*argv) {
			switch (**argv) {
			case 'd':
				debug++;
				break;
			...
			default:
				usage ();
			}
		}
	}
	...
}

The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell.  With the modification, the compiler will prevent this with
an
	error: increment of read-only location '*argv'

N.B.: The code above can be trivially rewritten like this:

	while (--argc > 0 && **++argv == '-') {
		char *arg = *argv;
		while (*++arg) {
			switch (*arg) {
			...

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2010-07-04 23:55:42 +02:00

84 lines
2.1 KiB
C

/*
* (C) Copyright 2003
* Stefan Roese, esd gmbh germany, stefan.roese@esd-electronics.com
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <command.h>
#include <pci.h>
#include <pci_ids.h>
#include <asm/4xx_pci.h>
#if defined(CONFIG_CMD_BSP)
/*
* Set device number on pci board
*/
int do_setdevice(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int idx = 1; /* start at 1 (skip device 0) */
pci_dev_t bdf = 0;
u32 addr;
while (bdf >= 0) {
if ((bdf = pci_find_device(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_405GP, idx++)) < 0) {
break;
}
printf("Found device nr %d at %x!\n", idx-1, bdf);
pci_read_config_dword(bdf, PCI_BASE_ADDRESS_1, &addr);
addr &= ~0xf;
*(u32 *)addr = (bdf & 0x0000f800) >> 11;
printf("Wrote %x at %x!\n", (bdf & 0x0000f800) >> 11, addr);
}
return 0;
}
U_BOOT_CMD(
setdevice, 1, 1, do_setdevice,
"Set device number on pci adapter boards",
""
);
/*
* Get device number on pci board
*/
int do_getdevice(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
u32 device;
char str[32];
device = *(u32 *)0x0;
device = 0x16 - device; /* calculate vxworks bp slot id */
sprintf(str, "%d", device);
setenv("slot", str);
printf("Variabel slot set to %x\n", device);
return 0;
}
U_BOOT_CMD(
getdevice, 1, 1, do_getdevice,
"Get device number and set slot env variable",
""
);
#endif